ProjectSummary/Abstract Timelyandaccurateregulationofgeneexpressionisrequiredforpropergrowth,development, andresponsetoenvironmentalstimuli.Acompleteunderstandingofthemechanisms employedtoregulategeneexpressionisnecessarytocombattheaberrantregulationthat underliesmanyhumandevelopmentalconditionsandailments,includingcancer.Thelong-term goalsofthisproposalaretodeterminethemechanicsofRNAsynthesisbyDNA-dependent multi-subunitRNApolymerases(RNAPs),theregulationimposedonRNAPbyconserved proteinfactors,selecttemplatesequencesandchromatin-barriers,andtospecifically characterizetheavailablemechanismstohaltRNAsynthesisandterminatetranscription.The proposedexperimentstakeadvantageofanestablishedinvivoandinvitroarchaeal transcriptionsystemfromthemarinehyperthermophilicorganismThermococcuskodakarensis. Archaeaoffertheadvantagesoffarlesscomplexitybuthomologyinmanyfeaturesofhuman molecularbiology,specificallyconservationofRNAPstructureandfunctionandhistone-based chromatin.Wewillcharacterizefactor-dependentandintrinsictranscriptiontermination, polarity,theconsequencesofDNAdamageontranscriptionelongationandtermination,andthe roleofglobaltranscriptionregulationinarchaealphysiology.Theresultsobtainedwill determinethestructuresandsequencesthatsupporttranscriptionelongationcomplexstability, describethemechanicsofterminationandallowcomparisonsofterminationmechanismsin eachdomainoflife,andprovideinsighttocontrolandultimatelymanipulategeneexpressionto counteravarietyofdiseasesandailmentsaffectinghumanhealth.